The present invention is concerned with a digital data recording and playback system which includes an optical recording and playback head, and which is capable of recording and retrieving digital data representing digital or analog signals onto and from a stationary optical storage card at random access memory speeds.
The system and head of the invention finds particular utility in the system described in co-pending application Ser. No. 619,098 filed Nov. 28, 1990, in the name of the present inventor.
The co-pending application discloses a digital broadcast system for the transmission of production quality stereo audio program material, video program material, and other data. The system described in the co-pending application comprises a plurality of transceiver units, each capable of operating in a number of modes, that is, in recording, transmitting, receiving and playback modes.
In the transmitting mode, one of the transceiver units in the system of the Co-Pending Application is capable of transmitting video or stereo audio data in digital form, either in real time or at high speeds, to other transceiver units over a selected common channel, such as a fiber optic, cellular UHF wave, microwave, satellite wave. In the receiving mode, the transceiver unit is capable of receiving data from the other units of the system of the Co-Pending Application in digital form, and of converting the received data back to its original analog form.
The optical storage card which is used in conjunction with the system and optical recording and playback head of the present invention is an optically encoded data card which may be of a size, for example, of a usual credit card. Both sides of the card may be utilized, and the card may have the capability of storing approximately a one half gigabyte of digital data on each side, which is the equivalent of approximately one double-sided record album per side, without compression of data.
Unlike the usual prior art video or compact disc, the optical storage card used in conjunction with the optical recording and playback head of the invention does not spin or move; and the elimination of the mechanical drive, and other requirements, results in significant accelerated write and access speeds and a cost reduction.
In the practice of the invention, the optical storage card is inserted into a slot in the housing of the optical recording and playback head, is precisely seated in the slot, and is scanned by alternating laser beams. The card itself is not susceptible to damage by normal handling, and it may be carried in a wallet or purse.